package com.haoxuer.discover.data.core;

import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Modifier;
import java.util.Locale;
import org.springframework.util.Assert;

public class MyBeanUtils {
  /**
   * 直接读取对象属性值,无视private/protected修饰符,不经过getter函数.
   */
  public static Object getFieldValue(final Object object,
                                     final String fieldName) {
    Field field = getDeclaredField(object, fieldName);

    if (field == null) {
      throw new IllegalArgumentException("Could not find field ["
          + fieldName + "] on target [" + object + "]");
    }

    makeAccessible(field);

    Object result = null;
    try {
      result = field.get(object);
    } catch (IllegalAccessException e) {
      throw new RuntimeException("never happend exception!", e);
    }
    return result;
  }

  /**
   * 直接设置对象属性值,无视private/protected修饰符,不经过setter函数.
   */
  public static void setFieldValue(final Object object,
                                   final String fieldName, final Object value) {
    Field field = getDeclaredField(object, fieldName);

    if (field == null) {
      throw new IllegalArgumentException("Could not find field ["
          + fieldName + "] on target [" + object + "]");
    }

    makeAccessible(field);

    try {
      field.set(object, value);
    } catch (IllegalAccessException e) {
      throw new RuntimeException("never happend exception!", e);
    }
  }

  /**
   * 循环向上转型,获取对象的DeclaredField.
   */
  protected static Field getDeclaredField(final Object object,
                                          final String fieldName) {
    Assert.notNull(object);
    return getDeclaredField(object.getClass(), fieldName);
  }

  /**
   * 循环向上转型,获取类的DeclaredField.
   */
  @SuppressWarnings("unchecked")
  protected static Field getDeclaredField(final Class clazz,
                                          final String fieldName) {
    Assert.notNull(clazz);
    Assert.hasText(fieldName);
    for (Class superClass = clazz; superClass != Object.class; superClass = superClass
        .getSuperclass()) {
      try {
        return superClass.getDeclaredField(fieldName);
      } catch (NoSuchFieldException e) {
        // Field不在当前类定义,继续向上转型
      }
    }
    return null;
  }

  /**
   * 强制转换fileld可访问.
   */
  protected static void makeAccessible(final Field field) {
    if (!Modifier.isPublic(field.getModifiers())
        || !Modifier.isPublic(field.getDeclaringClass().getModifiers())) {
      field.setAccessible(true);
    }
  }

  public static Object getSimpleProperty(Object bean, String propName)
      throws IllegalArgumentException, SecurityException,
      IllegalAccessException, InvocationTargetException,
      NoSuchMethodException {
    return bean.getClass().getMethod(getReadMethod(propName)).invoke(bean);
  }

  private static String getReadMethod(String name) {
    return "get" + name.substring(0, 1).toUpperCase(Locale.ENGLISH)
        + name.substring(1);
  }
}
